Package org.apache.calcite.util.mapping

Class Mappings.PartialMapping

java.lang.Object

org.apache.calcite.util.mapping.Mappings.AbstractMapping

org.apache.calcite.util.mapping.Mappings.FiniteAbstractMapping

org.apache.calcite.util.mapping.Mappings.PartialMapping

All Implemented Interfaces:

java.lang.Iterable<IntPair>, Mapping, Mappings.CoreMapping, Mappings.FunctionMapping, Mappings.SourceMapping, Mappings.TargetMapping

Direct Known Subclasses:

Mappings.SurjectionWithInverse

Enclosing class:

Mappings

public static class Mappings.PartialMapping
extends Mappings.FiniteAbstractMapping
implements Mapping, Mappings.FunctionMapping, Mappings.TargetMapping

A mapping where a source has at most one target, and every target has at most one source.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
private class	Mappings.PartialMapping.MappingItr	Mapping iterator.

Field Summary

Fields

Modifier and Type	Field	Description
private MappingType	mappingType
protected int[]	sources
protected int[]	targets

Constructor Summary

Constructors

Modifier	Constructor	Description
private	PartialMapping(int[] sources, int[] targets, MappingType mappingType)
	PartialMapping(int sourceCount, int targetCount, MappingType mappingType)	Creates a partial mapping.
	PartialMapping(java.util.List<java.lang.Integer> sourceList, int sourceCount, MappingType mappingType)	Creates a partial mapping from a list.

Method Summary

Modifier and Type	Method	Description
private static void	assertPartialValid(int[] sources, int[] targets)
void	clear()	Removes all elements in the mapping.
MappingType	getMappingType()	Returns the mapping type.
int	getSourceCount()	Returns the number of sources.
int	getSourceOpt(int target)
int	getTargetCount()	Returns the number of targets.
int	getTargetOpt(int source)	Returns the target that a source maps to, or -1 if it is not mapped.
Mapping	inverse()
boolean	isIdentity()	Returns whether this mapping is the identity.
protected boolean	isValid()
java.util.Iterator<IntPair>	iterator()	Returns an iterator over the elements in this mapping.
void	set(int source, int target)
int	size()	Returns the number of elements in the mapping.

Methods inherited from class org.apache.calcite.util.mapping.Mappings.FiniteAbstractMapping

equals, hashCode

Methods inherited from class org.apache.calcite.util.mapping.Mappings.AbstractMapping

getSource, getTarget, toString

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Methods inherited from interface org.apache.calcite.util.mapping.Mappings.SourceMapping

getSource

Methods inherited from interface org.apache.calcite.util.mapping.Mappings.TargetMapping

getTarget

Field Detail

sources

protected final int[] sources

targets

protected final int[] targets

mappingType

private final MappingType mappingType

Constructor Detail

PartialMapping

public PartialMapping(int sourceCount,
                      int targetCount,
                      MappingType mappingType)

Creates a partial mapping.

Initially, no element is mapped to any other:

Example

source	0	1	2
target	-1	-1	-1

Example

target	0	1	2	3
source	-1	-1	-1	-1

Parameters:

sourceCount - Number of source elements

targetCount - Number of target elements

mappingType - Mapping type; must not allow multiple sources per target or multiple targets per source

PartialMapping

public PartialMapping(java.util.List<java.lang.Integer> sourceList,
                      int sourceCount,
                      MappingType mappingType)

Creates a partial mapping from a list. For example, PartialMapping({1, 2, 4}, 6) creates the mapping

Example

source	0	1	2	3	4	5
target	-1	0	1	-1	2	-1

Parameters:

sourceList - List whose i'th element is the source of target #i

sourceCount - Number of elements in the source domain

mappingType - Mapping type, must be MappingType.PARTIAL_SURJECTION or stronger.

PartialMapping

private PartialMapping(int[] sources,
                       int[] targets,
                       MappingType mappingType)

Method Detail

getMappingType

public MappingType getMappingType()

Description copied from interface: Mappings.CoreMapping

Returns the mapping type.

Specified by:

getMappingType in interface Mapping

Specified by:

getMappingType in interface Mappings.CoreMapping

Specified by:

getMappingType in interface Mappings.FunctionMapping

Specified by:

getMappingType in interface Mappings.SourceMapping

Returns:

Mapping type

getSourceCount

public int getSourceCount()

Description copied from interface: Mapping

Returns the number of sources. Valid sources will be in the range 0 .. sourceCount.

Specified by:

getSourceCount in interface Mapping

Specified by:

getSourceCount in interface Mappings.FunctionMapping

Specified by:

getSourceCount in interface Mappings.SourceMapping

Specified by:

getSourceCount in interface Mappings.TargetMapping

Overrides:

getSourceCount in class Mappings.AbstractMapping

getTargetCount

public int getTargetCount()

Description copied from interface: Mapping

Returns the number of targets. Valid targets will be in the range 0 .. targetCount.

Specified by:

getTargetCount in interface Mapping

Specified by:

getTargetCount in interface Mappings.SourceMapping

Specified by:

getTargetCount in interface Mappings.TargetMapping

Overrides:

getTargetCount in class Mappings.AbstractMapping

clear

public void clear()

Description copied from interface: Mapping

Removes all elements in the mapping.

Specified by:

clear in interface Mapping

size

public int size()

Description copied from interface: Mapping

Returns the number of elements in the mapping.

Specified by:

size in interface Mapping

Specified by:

size in interface Mappings.CoreMapping

inverse

public Mapping inverse()

Specified by:

inverse in interface Mappings.SourceMapping

Specified by:

inverse in interface Mappings.TargetMapping

iterator

public java.util.Iterator<IntPair> iterator()

Description copied from interface: Mapping

Returns an iterator over the elements in this mapping.

This method is optional; implementations may throw UnsupportedOperationException.

Specified by:

iterator in interface java.lang.Iterable<IntPair>

Specified by:

iterator in interface Mapping

Overrides:

iterator in class Mappings.FiniteAbstractMapping

isValid

protected boolean isValid()

assertPartialValid

private static void assertPartialValid(int[] sources,
                                       int[] targets)

set

public void set(int source,
                int target)

Specified by:

set in interface Mappings.TargetMapping

Overrides:

set in class Mappings.AbstractMapping

getSourceOpt

public int getSourceOpt(int target)

Specified by:

getSourceOpt in interface Mappings.SourceMapping

Specified by:

getSourceOpt in interface Mappings.TargetMapping

Overrides:

getSourceOpt in class Mappings.AbstractMapping

getTargetOpt

public int getTargetOpt(int source)

Description copied from interface: Mappings.FunctionMapping

Returns the target that a source maps to, or -1 if it is not mapped.

Specified by:

getTargetOpt in interface Mappings.FunctionMapping

Specified by:

getTargetOpt in interface Mappings.SourceMapping

Specified by:

getTargetOpt in interface Mappings.TargetMapping

Overrides:

getTargetOpt in class Mappings.AbstractMapping

isIdentity

public boolean isIdentity()

Description copied from interface: Mapping

Returns whether this mapping is the identity.

Specified by:

isIdentity in interface Mapping

Specified by:

isIdentity in interface Mappings.SourceMapping

Overrides:

isIdentity in class Mappings.AbstractMapping